1. Field of the Invention
The invention relates to spoked wheels.
2. Relation to the Prior Art
Wheels for small carts, tricycles, lawnmowers and miscellaneous uses have evolved for economy of manufacture. A wheel can be molded in one piece of plastic and then a tire stretched over its rim. The one piece wheel has been made with a solid center or with molded-in spokes for decorative appearance. A common metal wheel uses two stamped pieces of steel welded together with a tube inserted at the center for an axle bearing and a tire stretched over the rim. The plastic one uses two pieces while the metal one uses four. Because of a distrust for plastic, people will pay more for the metal one. People will also pay more for a spoked wheel because traditionally it is accepted as higher quality and looks more elegant.
Hand-fitted spokes commonly are engaged at the hub and sprung into holes in the rim where they are secured by threaded fasteners. This involves considerable handwork and thus becomes expensive as a manufacturing process. To reduce this expense, sophisticated equipment has been developed with which the spokes are automatically positioned and welded to the rim, which is thereafter curved into a circle and its ends welded together. A hub is then positioned at the center and the spoke ends are fitted into slots in the hub and welded. Disks, simultaneously welded over the ends of the hub, provide axle bearings.
This works well and is economical in manufacture. However the welded ends are too rigid and do not allow for the constantly changing stresses of a rolling wheel. Spokes held in place less rigidly have proven to last longer.